Abstract: A disk system that conducts diagnoses of magnetic heads at regular or irregular interval to detect occurrence of unwritable failure. The history of regions on magnetic recording media where write operations took place is managed and a region where an unwritable failure occurred is specified. Data that corresponds to the unwritable failure is recovered by taking advantage of the redundancy of a RAID system. The disk system includes a unit that, upon reading data, checks whether the data to be read was written on the magnetic recording media through a normal write function. Through this, old data is prevented from being sent to host devices as a result of unwritable failure, and unwritable failures can be dealt with without increasing the processing time to detect unwritable failures.

Abstract: A disk system that conducts diagnoses of magnetic heads at regular or irregular interval to detect occurrence of unwritable failure. The history of regions on magnetic recording media where write operations took place is managed and a region where an unwritable failure occurred is specified. Data that corresponds to the unwritable failure is recovered by taking advantage of the redundancy of a RAID system. The disk system includes a unit that, upon reading data, checks whether the data to be read was written on the magnetic recording media through a normal write function. Through this, old data is prevented from being sent to host devices as a result of unwritable failure, and unwritable failures can be dealt with without increasing the processing time to detect unwritable failures.

Abstract: A magnetic recording subsystem comprises a channel unit, a magnetic recording control unit having a data buffer for temporarily storing data blocks of data transferred from the channel unit and a plurality of magnetic recording units connected to the magnetic recording control unit. When the data is stored into the data buffer, a block number is assigned to each data block. When the data is read from the data buffer and to be stored into a designated magnetic recording unit, the block number supplied from the data buffer and the block number assigned when the data was stored into the data buffer are compared, and then the data is stored into the magnetic recording unit.

Abstract: When the mount and demount operation of information media are achieved between an information medium storage shelf and a plurality of recording/playback apparatuses by use of a plurality of handling devices, in order to execute the operations in a concurrent fashion without causing an interference between the handling devices for an increased operation efficiency, the area of the storage shelf and at least one of the recording/playback apparatuses are respectively subdivided into a plurality of subareas so as to process the obtained subareas by the plurality devices respectively associated therewith.

Abstract: A data transfer speed control apparatus for effecting data transfer between semiconductor storage devices and CPU channel devices having maximum transfer speeds different from each other has connection line setting sections indicating the maximum transfer speeds of the semiconductor storage devices and the CPU channel devices. When data transfer between one of the semiconductor storage devices and one of the channel devices is to be made, a transfer speed determining section determines an actual speed of data transfer between the one semiconductor storage device and the one channel device on the basis of the indicated maximum transfer speeds of the one semiconductor storage device and the one channel device to be that one of both the maximum transfer speeds which is lower. The transfer speed of the semiconductor storage device and the channel device is set to the transfer speed determined by the transfer speed determining section.